docs: def get_witness_for_key_prefix(db, node_hash, key):
      """
      Get all witness given a keypath prefix.
      Include
  
      1. witness along the keypath and
      2. witness in the subtrie of the last node in keypath
      """
      validate_is_bytes(key)
  
      return tuple(_get_witness_for_key_prefix(db, node_hash, encode_to_bin(key)))